Example use

{% set feed = craft.rssatomReader.feed('http://open.live.bbc.co.uk/weather/feeds/en/6296595/observations.rss') %}
{% if feed %}
h1 {{ feed.channel.item.title }}
{% endif %}

the feed function also accept cache duration and curl timeout options (both in seconds) feed($url = null, $cache_duration = 86400, $timeout = 1000)